I've actually seen this for an eternity but never thought to ask until today while doing my regular aphid check. (Incidentally, whoever said aphids don't like basil clearly had their head somewhere else.)

Once early spring rolls around and I have plants and seeds out, I will almost always find thread of a web (a single string) cast across at least one thing each day. I have never found the culprit and I remove the thread each time I spot one, particularly noticeable when the sun hits at the right angle.

There doesn't appear to be any damage as a result of this, and the "thread" is often cast from one planter straight to another container, or I've seen it go from planter to straight across a 6 pack seed cell, etc. i remember this used to happen to my in-ground plants too, and I've never been able to find the culprit spider (I assume it's some kind of spider) but we do play this game all summer long.

I suppose I could just have a random spider hanging out on this balcony somewhere but you'd think it would try to make a home in one corner rather than straight across several plants. Doesn't seem very logical or conducive to building a real web.

I was just wondering if anyone also had this and if it's a common thing/pest.

Grace